Re: polgalois() inconsistency

[Karim BELABAS <Karim.Belabas@math.u-psud.fr>]

On Fri, 7 Nov 2003, Igor Schein wrote:
> ? default(new_galois_format,0)
>    new_galois_format = 0 (off)
> ? polgalois(x^3-2)
> [6, -1, 2]
> ? default(new_galois_format,1)
>    new_galois_format = 1 (on)
> ? polgalois(x^3-2)
> [6, -1, 2]
>
> I expect the first result to say [6,-1,1] according to the manual.
> Also, in the manual both new_galois_format and newgaloisformat occur.
> I guess the former is correct.

I hadn't noticed that: from the normalized output (new_galois_format = 1),
there's no way to distinguish S_3 as a subgroup of S_3 (i.e polynomial of
degree 3) and as a subgroup of S_6 (poly of degree 6). And in the old format,
they get two different names.

So the way I implemented new_galois_format (get normalized result, then
translate for backward compatibility if necessary) can't work because of this
single example. polgalois itself has to know about new_galois_format.

Fixed in CVS [ and checked / taken into account in 'make test-galois' ].

    Karim.
-- 
Karim Belabas                     Tel: (+33) (0)1 69 15 57 48
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